Abstract: Theodore Maiman in 1960 introduced the first solid state ruby LASER. Since then LASERs have come a long way with numerous applications in the field of medicine and dentistry. In dentistry LASERs are now in vogue and are now becoming a part of the dentist’s armamentarium for endodontic , restorative , periodontal and implant therapies. This paper gives an insight to the basics of LASER physics, various types of LASERs, their interactions with biologic tissues and their uses in Periodontics.